Iconic Shield is a uncommon Artifact — Equipment card from Marvel Super Heroes Commander (MSC), collector number 520. Current market price: $0.21 (foil $10.00), TCGplayer market prices via Scryfall.
Equipped creature gets +1/+2 and has "Whenever this creature attacks, another target attacking creature gains indestructible until end of turn." (Damage and effects that say "destroy" don't destroy it.) Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)